Chairs for extended seating applications, such as banquet halls and conference rooms, are preferably comfortable, durable, and either stackable or nestable for storage purposes. Traditional stackable banquet chairs include a pair of inverted-U-shaped leg members attached to opposite sides of a generally horizontal seat. A generally L-shaped back support frame interconnects with the leg members and extends upwardly from the rear of the seat to support a back cushion. This type of chair may be stacked by placing the inverted-U-shaped leg members of one chair over the top of the leg members of another chair, such that the seat of the upper chair is supported just above the seat of the lower chair. Examples of traditional stackable banquet chairs are shown in U.S. Pat. No. 3,102,733 to Burnett and U.S. Design Pat. No. D180,996 to Cramer. While this type of chair has wide applicability, some property owners and interior designers prefer chairs that do not look like a traditional stacking chair. These traditional stacking chairs have the leg members completely exposed at the sides of the chairs. Some users prefer legs or leg members that are less visible.
The above-described chair is generally referred to as a stacking chair, because the leg members of one chair rest directly on the leg members of a lower chair creating a secure leg-on-leg stack. Multiple chairs may be securely stacked on top one another with this design.
An alternative to stacking chairs is so-called nesting chairs. Nesting chairs come in a variety of styles and are distinguished from stacking chairs in that the underside of a seat frame of one chair rests atop the seat cushion of a lower chair when the chairs are nested. An example of a nesting chair, as defined herein, is illustrated in U.S. Pat. No. 5,524,963 to Barile. An advantage with nesting chair designs is that the chair designer may configure the chair legs to be less exposed than with traditional stacking chairs.
Because chairs for extended seating applications are often used for extended periods of time, seating designers are continuously seeking ways to improve the comfort of the chairs. It is preferred that the seat back flex somewhat with respect to the seat cushion to improve comfort. However, providing a flexible seat back presents significant challenges to seat designers, especially where the chair must also stack or nest. Examples of stacking or nesting chairs with seat backs that flex relative to the seat bottom are shown in the following U.S. Pat. No. 4,549,764 to Haedo; U.S. Pat. Nos. 4,603,904, 4,869,552, and 5,039,163 to Tolleson; U.S. Pat. No. 4,938,532 to Burgess; and U.S. Pat. No. 5,902,012 to Han. The designs disclosed in these patents are generally complicated and costly to manufacture, limiting their applicability. Also, the designs are generally limited to stacking chairs wherein the legs of the chairs are completely exposed.
Another nesting chair design with a flexible back is shown in FIGS. 1 and 2. In these figures, the seat cushion and seat back are shown in phantom, to make the construction details of the chair more easily visible. This chair 10 includes a seat cushion 12 supported by symmetrical left and right leg members 14 and 16. While not shown, the seat cushion 12 includes a cushion base, which is typically a piece of flat wood. The leg members 14 and 16 are screwed or bolted directly to this seat cushion base so as to interconnect the cushion with the leg members and to maintain the relationship between the leg members. A generally L-shaped seat back bracket 18 has a lower end interconnected with the same seat cushion base and an upper end that extends up and interconnects with the seat back 20. Bracket 18 is preferably flexible enough that the seat back 20 can flex somewhat with respect to the seat cushion 12.
As will be clear to those of skill in the art, the seat cushion 12 takes a large amount of load in order to rigidly interconnect the various portions of the chair. That is, all forces transmitted between the seat back 20, seat cushion 12 and leg members 14 and 16 are carried by the seat cushion itself. This loading can be substantial, especially when a chair is dropped, a heavy occupant sits in the chair, or the occupant tilts the seat backwardly to lift the front leg members off the floor, or otherwise abuses the chair. This design also has the shortcoming that if an owner wishes to reupholster the seat cushion 12, the chair 10 must be completely disassembled. In other words, the leg members 14 and 16 do not form a self-supporting base.